Glossary of Riding Mower Engine Terms

Air Filter System

Removes particles such as dust, dirt and debris from the air and keeps it from getting into your engine.

Advanced Debris Management System Air cleaner system that forces air past the element, where large debris passes through ejection slots. Removes large dirt and debris particles for a longer lasting air cleaner element and superior engine protection.

Dual-Clean™ Combination automotive-style paper filter and foam pre-cleaner for added protection against dirt and debris. Two levels of protection against contaminants protect and improve engine durability.

Foam Reusable washable material that uses surface oil to trap dirt and debris. Simple and convenient filter system to protect the engine.

Oval Dual Sealing Larger filtering capacity with two sealing surfaces for maximum prevention of dirt ingestion. Allows more airflow for improved performance, while defending against dirt ingestion for extended engine life.

Tool-Less Cover Air cleaner cover that can be removed without using a tool. Makes it easy to change the air cleaner.

Balancer System

Mechanical device that reduces the vibration caused by the moving forces of the piston. Provides less vibration and smoother operation.

Pulsa Prime Diaphragm within the carburetor is actuated by the natural vacuum vented through the engine block to pump fuel to the combustion chamber. Simple and reliable self-actuated fuel delivery system.

Fuel Shut-off Valve

Manual device inserted into the fuel line that when turned, shuts off fuel flow to carburetor. This is useful for shutting off the fuel flow during transportation or storage.

Fuel Filter

Filter inserted into fuel line that screens out dirt and debris from fuel supply.

Governor

Prevents over-speeding of the engine by holding RPMs at a constant speed and also maintains speed under heavy load.

Air Vane Uses air from the rotating flywheel fan to monitor engine RPMs so the governor can maintain the selected engine speed. Simple self-adjusting system that senses load and maintains engine speed.

Mechanical This system uses gears and flyweights inside the crankcase to sense speed and detect changes in the load to adjust speed. Controls the engine speed to deliver more usable power under heavy usage.

High Oil Fill

Oil tube is mounted to be accessible at the top of engine. Provides easy access to check and fill oil.

Horsepower

Measurement of an engine's rate of doing work over time (rpm x torque / 5,252). Power to get the work done.

Ignition System

Activates and controls the combustion of fuel in an engine.

Magnetron® Electronic ignition system generated by a rotating magnet and coil assembly. Ensures dependable starts with no maintenance required.

Lubrication System

A system that stores, cleans, cools, and re-circulates oil through the engine to lubricate and cool its moving parts.

Full Pressure Lubrication Similar to an automobile engine that continuously delivers oil under pressure to critical engine components for maximum lubrication and long engine life. A high-efficiency pump in the oil pan supplies lubricant to the crankshaft and connecting rod-bearing surfaces.

Pressure Lubrication A controlled flow of clean oil to bearings for less wear and longer engine life. A high-efficiency pump in the oil pan supplies lubricant to the crankshaft and connecting rod-bearing surfaces. The Pressure Lubrication System incorporates a premium spin-on oil filter.

Splash Lubrication A gear-driven dipper or slinger in the crankcase distributes oil to components, preventing clogging of small passages. On horizontal crankshaft engines, the dipper is attached to the connecting rod. It picks up oil from the reservoir and spreads it across bearing surfaces as the piston travels through the cylinder. On vertical crankshaft engines, a spinning gear with paddles is immersed in oil and slings lubricant throughout the crankcase.

Mechanical Compression Release

Device that keeps a valve open to release combustion chamber pressure and automatically returns to normal with the engine's centrifugal forces. Automatically reduces compression force to provide smooth, easy starts.

Muffler

Designed to reduce noise, improve performance and resist corrosion.

Lo-Tone™ Benefits - Quiet operation and good tone quality.

Super Lo-Tone™ Benefits - Quieter operation and better tone quality.

Quiet-tone Max Benefits - Quietest operation and best tone quality.

Oil Capacity (oz.)

The recommended amount for holding, storing, or accommodating reserve oil.

Oil Cooler

Oil Fill

Allows access to check and fill oil to prevent over or under filling of oil.

Starting System

Electric Start Uses a battery-powered motor to start the engine via a key switch or button. Hassle-free starting. Just turn the key and go.

Electronic Fuel Management (EFM) A system that electronically monitors time, engine speed and temperature to simplify and optimize engine startup for ride engines. Provides the easiest starting system for ride engines.

Prime 'N Pull™ System that requires priming to deliver fuel directly to start an engine. Delivers the right amount of fuel to system for dependable starting.

Ready Start™ System that automatically senses engine temperature to deliver the right amount of fuel to the carburetor. Does not require priming or choking. Just pull for power.

4" Rewind Starter Spring-return mechanism that returns the rope and handle to start position. Reliable self-returning starter that saves time and energy.

Torque

A measurement of force needed to cause an object to rotate. Power to get the work done.

Valve Design

Any of numerous mechanical devices by which the flow of liquid, gas, or loose material in bulk may be started, stopped, or regulated by movable parts that open, shut, or partially obstruct one or more ports or passageways.

OHV Configuration with the inlet and exhaust valves located in the cylinder head above the pistons. Better optimized performance that runs cooler and cleaner for longer engine life and improved fuel economy.

DOV® OHV configuration with direct actuation of the valves through a unique lever system. Patented new design that delivers more responsive power, less noise, and smoother operation.

OHC Configuration with the cam shaft, inlet and exhaust valves located in the cylinder head above the pistons.

Side Configured with both valves side by side within the cylinder block, typically parallel to the cylinder bore. Simple and reliable with less overall maintenance.

Weight (lbs.)

Total weight measurement of standard engine configuration.

XRD

Over 80 upgrades to the Extended Life Series™ and Intek™ Series of riding mower engines that provide eXtra Reliability and Durability, easier starting, quieter operation, and cleaner emissions.

ZTR Package (Heavy-Duty Package)

A group of features designed to maximize the durability of a V-Twin engine for large riding lawn mower and zero-turn radius tractor applications. Includes a pressed-in sleeve bearing to accommodate a high belt load, a super-polished crankpin bearing, and a shock load resistant crankshaft. A high-output starter motor for easier starting under load is optional.